Republic's ownership group restructured because that's what MLS demanded so I fail to see how that's a "black mark" on them. Second, given the AAF business model where the league owns the team, which makes a lot of sense for a startup league, why would Burkle want to look into a franchise? Wouldn't make sense for him. Guys like Burkle want control and I don't see a scenario where he can invest and get the kind of control he'd want.
However, if Sacramento happened there would be more interest in an intrastate rival in San Diego over an artificially created one with Portland. Fans here don't view Portland as a rival even when it comes to Kings/Blazers and San Diego is closer than Portland.

I would say no. Papa Murphy's Park is more along the lines of a temporary structure. I'd doubt the locker room facilities would be adequate for a football team with all of the equipment they have. What it has going for it football wise would be more than adequate parking for tailgating purposes. If given the choice of Papa Murphy's Park, Hornet Stadium or Hughes Stadium at Sac City College, Hornet Stadium would be the best bet.
Remember too that The Railyards stadium is still at least two years away from when an announcement would be made on admission into MLS. The stadium won't go up without joining MLS first.

FTFY.
With his purchase of a majority interest in the Republic, Burkle also is the owner of The Railyards stadium site. The stadium is to be built with private funding the city only providing infrastructure improvements in the area. If it comes to whether an AAF team would play in The Railyards that decision would be Burkle's, not the city's.

Also in the world of money talks, the AAF lacks both the actual capital (with their demonstrated financial issues) and the political capital to get the city or the University to change their minds. Knowing how Berkeley is I'd doubt they'd change their minds under any circumstance. Now that said I think Sacramento and Hornet Stadium would be a fine venue for an AAF team should they a) last for another season, and b) relocate a team. If something like that happened I'd be inclined to walk over and catch a couple of games.

Thanks for bringing back memories that took years of therapy to repress . My cars were the true embodiment of all things Jets. Looked good on paper but couldn't execute, last place, wheels falling off halfway down the ramp... Those were the days!